I'm sorry to say, but unfortunately this is 100% a scam. A few key flags:

- sending you a cc payment which can be a stolen number, and asking for you to shell out cash to someone else. Big no-no.

- suddenly upping his order with MORE cash for you to shell out, once he realizes he has you.

- hotmail email account as you mentioned. Untraceable. I'm sure their government has official email domains and don't need hotmail.

- this one is an interesting catch. Notice in the email he sent you, how there are a few "double spaces" in the text. Two spaces in between words, instead of one space. Those extra spaces are around words and sentences that would need to be customized for your particular scam case. Meaning, he has a standard boilerplate email that he uses to scam people, only he has to customize it here and there with the details of each case, and hence the double spaces there because he is not being careful with the editing. Which makes it easier for us to spot

I haven't actually stayed at either property, but I visited both and based on the lobbies alone I like the Danieli better, but the Gritti was extremely nice as well. I can't recommend either one having stayed at the Westin.